• Journal of the Korean Data and Information Science Society
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• v.13 no.2
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• pp.285-294
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• 2002

The control chart is widely used tool for monitoring of the process. This paper deals with an interpretation of the process capability index(PCI) and process performance index(PPI) when the control chart is used for monitoring of the process. The main difference between the PCI and PPI is how we did estimate the process deviation. The PCI uses the within process variation and the PPI uses the total process variation, which is conceptually defined as sum of between process variation and within process variation. Easy interpretations of the PCI and PPI for field engineers are described. And some new approaches to interpretation of the process capability and performance index may be useful in early stabilization of new process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.435-436
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• 2012

• Proceedings of the Korean Reliability Society Conference
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• 2000.11a
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• pp.375-384
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• 2000

The main objective of this paper to purpose a evaluating methods of process capability measures for exponential distributed quality characteristics. For correctly evaluating process capability , the first thing , exponential data is applied the Lilliefors test statistic to the null hypothesis of nornality. The next, exponential parameters is estimated in terms of MLE , ME , MME and then evaluated , respectively , process capability index based on exponential curved (Ιe) proposed by in this study and process capability indices based on Pearson system and Johnson system.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.195-203
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• 2008

The purpose of this study is to develop a guideline of process capability evaluation and to apply this guideline improving the quality of products, especially in the small and medium enterprises. In this study we deal in the concept of process capability evaluation, the calculation of process capability index, and the application of a case study. Man must compare the state of process with the standards in evaluating of the process capability. Control chart can be used as a yardstick for judgement for the long term period and the distribution shape of histogram for the short term period. Man should regard to the significant figure by the calculation of process capability index.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.1
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• pp.43-51
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• 2019

This research proposed the necessary capability of cyber security professional personnel for cyber security education and training. Cyber security professional personnel were required specialized capability because the curriculum of cyber security education and training is structured around practice and training. Based on the knowledge, skills, and attitudes of professors, we derive candidate capabilities and index through the results of precedent research. As a result, we derived capability such the candidate capability group as teaching qualification, expert knowledge, practical ability, lecture ability, and research ability, and detailed capability index was derived accordingly. Finally, based on the questionnaire results of the professors related to the information security, it was determined that the capability required for the cyber security education and training professional personnel were expert knowledge, practical ability, and lecture ability. Among the capabilities, executive ability means that they have to fulfil abundant executive experience due to the high proportion of practical training due to the characteristics of cyber security education and training.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.91-97
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• 2016

This study is concerned about the process capability index in single process. Previous process capability indices have been developed for the consistency with the nonconforming rate due to the process target value and skewness. These indices calculate the process capability by measuring one spot in an item. But the only one datum in an item reduces the representativeness of the item. In addition to the lack of representativeness, there are many cases that the uniformity of the item such as flatness of panel is absolutely important. In these cases, we have to measure several spots in an item. Also the nonconforming judgment to an item is mainly due to the range not due to the standard variation or the shift from the specifications. To imply the uniformity concept to the process capability index, we should consider only the variation in an item. It is the within subgroup variation. When the universe is composed of several subgroups, the sample standard deviation is the sum of the within subgroup variation and the between subgroup variation. So the range R which represents only the within subgroup variation is the much better measure than that of the sample standard deviation. In general, a subgroup contains a couple of individual items. But in our cases, a subgroup is an item and R is the difference between the maximum and the minimum among the measured data in an item. Even though our object is a single process index, causing by the subgroups, its analytic structure looks like a system process capability index. In this paper we propose a new process capability index considering the representativeness and uniformity.

• Journal of Korean Society for Quality Management
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• v.24 no.4
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• pp.90-102
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• 1996

Process incapability index which is intended to evaluate the process capability by measuring process incapability provides more detailed information by dividing information about the process mean and variance. But when the target value is not consistent with the center of specification, it is very difficult to evaluate the process capability accurately. Thus it is necessary to improve the existing process incapability index. The improved process incapability index can identify the variation of the process faster than other process capability indices when applied firstly, to the precision process which can be affected sensitively by the change of the process, secondly, to the ordinary process where cost difference from the change of process is noticeable. By using subindices such as inaccuracy index and imprecision index, it is easier for quality manager to find where the cause of the variation of process is, and to take necessary action in advance.

• International Journal of Quality Innovation
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• v.3 no.2
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• pp.74-83
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• 2002

Process capability indices as an important kind of indices are intended to provide single-number assessments of the inherent process capability to meet specification limits on quality characteristic(5) of interest. In this paper the condition for the application of process capability indices is analyzed. On the basis of process capability indices, dynamic process capability indices as a new kind of indices to show the current process capability are discussed and the condition for the application of dynamic process capability indices is exhibited. Comparison between process capability index and dynamic process capability index and comparison between $D_p$ and $D_pk$ are made and the conclusions provide the approach for process control. According to the requirement of process capability indices provided by customer, quality control based on process capability indices dynamic process capability indices is discussed.

• Journal of Korean Society for Quality Management
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• v.34 no.3
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• pp.66-72
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• 2006

The process capability indices are widely used to measure the capability of the process to manufacture items within the specified tolerance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. The index $C_p$ has been widely used in various industries to assess process performance. In this paper, we propose new testing procedure on assessing $C_p$ index for practitioners to use in determining whether a given process is capable. The provided approach is easy to use and the decision making is more reliable. Whether a process is clearly normal or nonnormal, our bootstrap testing procedure could be applied effectively without the complexity of calculation. A numerical result based on the proposed approach is illustrated.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.116-123
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• 2005

The traditional process capability indices Cp, Cpk, Cpm, $Cpm^+$ have been used to characterize process performance on the basis of univariate quality characteristics. Cp, Cpk consider the process variation, Cpm considers both the process variation and the process deviation from target and Cpm+ considers economic loss for the process deviation from target. In manufacturing industry, there is growing interest in quantitative measures of process variation under multivariate duality characteristics. The multivariate process capability index incorporates both the process variation and the process deviation from target or considers expected loss caused by the process deviation from target. This paper proposes multivariate capability index based on the expected loss derived from multivariate normal distribution.